mypros+
Error code reference

Haier Air Conditioner Error Code F6

Ambient temperature sensor failure (outdoor)

Haier codesHaier air conditioner codes

Ambient temperature sensor failure (outdoor). Outdoor LED1 flashes 12 times.

First step from the service manual

Check connector connection; if normal, check thermistor resistance; if normal, replace PCB.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for F6.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What F6 means on a Haier air conditioner

The F6 error code on a Haier air conditioner indicates a failure in the outdoor ambient temperature sensor. This thermistor is mounted on the outdoor unit and provides the main control board with real-time ambient temperature readings. The PCB uses this data to regulate compressor operation, refrigerant flow management, and defrost cycle timing. When the sensor signal falls outside the expected voltage or resistance range, the outdoor unit's LED1 will flash 12 times in sequence to signal the fault.

The ambient temperature sensor is a Negative Temperature Coefficient (NTC) thermistor, meaning its resistance decreases as temperature rises. A failure can occur in one of several ways: the thermistor element itself degrades or fails open/short, the wiring harness develops a break or short circuit, or the connector between the sensor and the PCB becomes loose or corroded. Any of these conditions will cause the PCB to read an implausible temperature signal and trigger the F6 code.

Diagnosis follows a clear sequence. The first step is to inspect the sensor connector at the outdoor PCB for proper seating, corrosion, or pin damage. If the connector is intact, the thermistor resistance should be measured and compared against the temperature-to-resistance chart for the unit. A thermistor reading that is open circuit, shorted, or far outside the expected range confirms sensor replacement is needed. If the resistance measures correctly and the connector is sound, the outdoor PCB itself is the likely fault and will require replacement.

Source: manufacturer service documentation.

Common causes of F6

  1. 01

    Loose or corroded sensor connector

    Wiring / connection

    The connector between the ambient temperature sensor and the outdoor PCB can work loose over time or develop corrosion, especially in humid environments. Reseating or cleaning the connector is the first step and costs nothing if no damage is present.

  2. 02

    Failed outdoor ambient thermistor

    Part replacement

    The NTC thermistor itself can fail open or short circuit due to age, moisture ingress, or physical damage. Measuring the thermistor resistance with a multimeter and finding an open circuit, a short, or a reading far outside the expected range confirms it needs replacement.

  3. 03

    Damaged sensor wiring harness

    Part replacement

    The wiring between the thermistor and the PCB can be pinched, broken, or chafed against the cabinet. Inspect the full length of the harness for visible damage and test continuity on each wire.

  4. 04

    Faulty outdoor PCB

    Part replacement

    If the sensor connector is secure and the thermistor resistance tests correctly, the outdoor main control board may have failed and is misreading or not reading the sensor signal at all. PCB replacement is the final step in this diagnostic sequence.

See the test procedure for each cause

Frequently asked questions about F6

What does F6 mean on a Haier air conditioner?
F6 indicates a failure in the outdoor unit's ambient temperature sensor. The outdoor LED1 will flash 12 times to signal this fault. The sensor is a thermistor that the control board relies on for accurate outdoor temperature data. When the signal is outside the expected range, the system logs F6 and alerts you to inspect the sensor circuit.
Can I fix the F6 error code myself?
Some steps are accessible to a knowledgeable DIYer. You can inspect the sensor connector on the outdoor unit for looseness or corrosion and reseat it if needed. Testing the thermistor with a multimeter is also possible if you are comfortable working around electrical components. However, if the PCB needs replacement, that work is best left to a certified HVAC technician.
Is it safe to keep running my Haier air conditioner with an F6 error?
Running the unit with an F6 fault is not recommended. The outdoor ambient temperature sensor is used to manage compressor operation and protect the system from running outside safe parameters. Without a valid temperature reading, the unit may operate inefficiently or risk damage to the compressor over time.
How much does it cost to repair an F6 error on a Haier air conditioner?
If the fix is simply reseating a loose connector, there is no parts cost involved. Replacing the thermistor sensor is generally an inexpensive repair, with parts typically ranging from $10 to $40 depending on the model. If the outdoor PCB requires replacement, costs rise significantly, often ranging from $150 to $400 or more including labor.
Will resetting my Haier air conditioner clear the F6 error code?
A power reset may temporarily clear the displayed code, but the fault will return if the underlying problem with the ambient temperature sensor or its circuit has not been resolved. Clearing the code without addressing the root cause does not fix the sensor and may allow the unit to run in a compromised state. A proper diagnosis of the connector, thermistor, and PCB is needed to permanently resolve F6.

Related Haier air conditioner codes

All Haier air conditioner codes
View all 47 Haier air conditioner codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass